Cranks/Rods/Cams

KTM 600 XC

No rider who has ever thrown a leg over KTM’s 525XC can call it slow— and if they have, they might need to take some time off for a mental rebuild. Stock, it will outrun just about any other sport quad on the market today, save for KTM’s own 505SX. The singleoverhead- cam, four-valve RFS Racing Four-Stroke) engine spent a good amount of time in KTM’s off-road motorcycles, achieving a level of refinement and performance we came to value when testing the biggest Katoom. In stock form, the 525XC is an open-class fighter—tons of power, comfortable Ohlins suspension, a lightweight chromoly frame and a whole lot of attitude make it one seri- ous performer. In the dunes, it’s a blast; the huge torque curve makes wheelies and huge roosts just a blip of the thumb throttle away. But what happens if you get bored? Surely some power-hungry ATV riders out there will grow tired of having only 45–50 horsepower. Then what? If you have a KTM, you call Thumper Racing....